Ulceration of the lower limbs affects a significant proportion of the population over the age of sixty. Although there are several forms of ulcer one of the more common is the venous leg ulcer, which is believed to result from failure of the valves within the venous system. The failure of these valves reduces the efficiency of return of blood from the limb and this is believed to correlate to the incidence of ulceration.
Venous leg ulcers are currently treated both by the use of a dressing to the wound and the application of compression to the affected limb. Compression is conventionally applied by either the use of bandages or stockings, with the tension within the fabric structure of these products generating compressive force. The effectiveness of the dressings, which allow the passage of water vapor from the wound, is impaired by the application of conventional compression materials, particularly bandages. Some of the wound exudates can leak around or through the dressing, creating wetness; this fluid contains enzymes that can cause maceration of the surrounding skin which is of course undesirable.
Bandages or stockings are furthermore uncomfortable to wear, especially in hot weather, as moisture cannot easily escape. With bandages and stockings, the bony prominences, such as the shin bone and ankle bone, receive concentrated pressure levels and therefore an under layer of soft non woven padding is also used, to pad the limb and make its cross section more circular.
This padding may also perform the function of absorbing any fluid that escapes from the dressing. However, it is a skilful and difficult to perfect job to locate the padding appropriately, and the bandages may subsequently move and dislodge the padding.
Compression may also be applied using a constrained air bladder, which solves some of the problems associated with the use of bandages and stockings. The air bladder itself is impermeable to vapor and this can therefore cause problems, as heat and moisture from sweat are trapped by the bladder.
Accordingly, there is a need for means for alleviating the problems associated with the use of known compression systems for leg ulcer patients.